AB0301 ANALYSIS OF INTESTINAL MICROBIOTA IN PATIENTS WITH OSTEOPOROSIS SECONDARY TO RHEUMATOID ARTHRITIS
Authors: A. M. Cabezas-Lucena, M. Morales-Águila, P. Ruiz-Limon, I. Moreno-Indias, N. Mena-Vázquez, S. Manrique Arija, A. Fernandez-Nebro
Journal: Annals of the Rheumatic Diseases (2022)

Objectives To analyse of intestinal microbiota in patients with osteoporosis (OP) secondary rheumatoid arthritis (RA). Methods Design : A cross-sectional observational study nested in a prospective cohort of incident RA patients. Patients : Patients with RA (ACR/EULAR 2010) from a prospective baseline cohort (incident cases between 2007-2011), &gt;16 years, from whom information on bone mineral densitometry (BMD) was collected. Protocol : all subjects were evaluated in a specialized outpatient unit. Clinical-analytical variables of the cut-off date and clinical history were registered. Blood, urine and faeces samples were obtained from all subjects. A BMD was done by dual energy X-ray absorptiometry (DXA) for osteoporosis diagnosis. Variables : Dependent variable: osteoporosis according World Health Organization (WHO) definitions. The fecal microbiota (continuous var., 0-100%) was analysed using the Ion Torrent S5 next-generation sequencing platform, and the sequences obtained were processed using the QIIME2 (Quantitative Insights Into Microbial Ecology 2) software. Others variables included demographics characteristics, comorbidities, inflammatory activity measured by mean accumulated Disease Activity Score-28 (DAS-28) throughout the disease, severity variables: smoking, erosions, anticitrullinated peptide antibody (ACPA) titres, rheumatoid factor (RF) and physical function measured by HAQ. Treatment with bDMARD (biological disease-modifying antirheumatic drug) and/or sDMARD (synthetic disease-modifying antirheumatic drug). Statistical Analysis : descriptive, bivariate using χ2 and T-Student followed by logistic multivariant regression model in patients with RA. (Vd: Osteoporosis). Results 110 patients with RA were included. The majority of the subjects were women (80%) with an average age of 56 years. The majority of patients were seropositive (81.8% with positivity for RF and 80% with positive for ACPA) and the accumulated DAS-28 average was 3. A total of 49/110 (44.5%) had normal BMD, 46/110 patients (41.8%) had densitometric osteopenia and 15/110 OP (13.6%). Patients with OP were older (p=0.025), higher RA length (p=0.003), higher CRP (p=0.046), higher inflammatory by DAS-28 (p=0.051) and higher ACPA titres (p=0.043). Furthermore, they showed higher levels of Lentisphaerae (p=0.035), Synergistetes (p&lt;0.001), Actinobacteria (p=&lt;0.001) y Verrucomicrobia (p=0.034). The variables independently associated with OP in RA were: age (OR [IC 95%],1.099 [1.012-1.193]; p=0.025), ACPA (OR [IC 95%],1.005 [1.001-1.010]; p=0.036), RA length (OR [IC 95%],1.039 [1.016-1.062]; p=0.001) y Actinobacteria (OR [95% CI] 1.124 [1.004-1.257]; p=0.042), R2=0.367. Conclusion Osteoporosis in Rheumatoid Arthritis is associated with severity factors as the age, the disease length or the presence of ACPA, as well as the Actinobacteria predominance in the intestinal microbiota. Table 1. Epidemiological, clinical and analytical characteristics of patients Variable Patients n=110 Epidemiological characteristics Age in years, mean (IQR) 55.9 (49.3-64.4) Sex, female; n (%) 88 (80.0) Tobacco Never smoker, n (%) 47 (42.7) Ex-smoker, n (%) 30 (27.3) Active smoker, n (%) 33 (30.0) Comorbidities High blood pressure, n (%) 28 (25.5) Diabetes Mellitus, n (%) 6 (5.5) Dyslipidemia, n (%) 25 (22.7) Cardiovascular Disease, n (%) 18 (16.4) BMI (Kg/m 2 ), mean (SD) 28.4 (5.1) Clinical and analytical characteristics RA evolution time, months, median (IQR) 93.2 (77.6-123.4) Diagnosis delay, months, median (IQR) 8.1 (4.5-17.0) Erosions, n (%) 68 (61.8) RF &gt;10, n (%) 90 (81.8) ACPA &gt;20, n (%) 88 (80.0) DAS-28 average, mean (±SD) 3.0 (0.7) HAQ average, median (IQR) 0.71 (0.3-0.9) sDMARD, n (%) 93 (84.5) bDMARD, n (%) 42 (38.1) Osteopenia, n (%) 46 (41.9) Osteoporosis, n (%) 15 (13.6) Disclosure of Interests Alba María Cabezas-Lucena: None declared, Maria Morales-Águila: None declared, Patricia Ruiz-Limon: None declared, Isabel Moreno-Indias: None declared, Natalia Mena-Vázquez: None declared, Sara Manrique Arija Speakers bureau: Abbvie, Gedeon, Jansen, Lilly, Menarini, MSD, Novartis, Pfizer, Roche, Sanofi, UCB, Consultant of: Abbvie, Jansen, Lilly, Novartis, Sanofi, Antonio Fernandez-Nebro: None declared